Physical association of Ras and cathepsins B and L in the conditioned medium of v-Ha-ras-transformed NIH3T3 cells.

Immunoblot analysis of the conditioned medium of v-Ha-ras-transformed NIH3T3 cells showed that Ras protein is secreted in the culture fluid. Because cathepsins L and B whose activities are inhibited by Ras are also secreted, possible association between Ras and cathepsins was investigated by immunoprecipitation and following immunoblot analysis. The results showed that Ras is physically associated with cathepsins B and L in the culture fluid.